Electric railway.



No. 675,050. Patented May 28, IBM. S. B. STEWART, In. ELECTRIC RAILWAY.

(Application filed Feb. 21, 1901'.)

(No Model.)

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Witnesses.

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NTTED terns ATENT Fluent SAMUEL B. STEXVART, JR., OF SCIIENECTADY, NElV YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEWV YORK.

ELECTRIC RAI LWAY.

SPECIFICATION forming part of Letters Patent No. 675,050, dated May 28, 1901.

- Application filed February 21, 1901- $erial No. 48,207. (No model.)

To (M wh'mn it may concern:

Be it known that I, SAMUEL B. STEWART, Jr., a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvementsin Electric Railways, (Case No. 1,753,) of which the following is a specification.

This invention relates to improvements in I0 electric railways of the type wherein the conductor consists of sections which are connected with the line or feeder successively as the car proceeds. These conductor-sections, which may be either rails or small studs, are adapted to be connected with the feeder by electromagnetic switches located any suitable place along the way, which switches are successively energized as the car proceeds by current flowing from one of the electromagnetic 2o switches which has already been closed. To

first obtain current to start the car, an electromagnetic switch is energized by an auxiliary source of current carried by the car. It is generally necessary in such systems, and especially when the electromagnets are in shunt to the car-motors, to have suitable resistances inserted in series with the magnetcoils to prevent the flow of an excessive current. These resistances have sometimes been carried by the car, as in the patent to Orehore, No. 536,828, but generally have been embodied in themechanical structure of the electromagnetic switches which are located along the way. It has been discovered in the 5 latter case that these resistances may be permitted to be out of circuit when the collect ing means carried by the car first engages with the conductor-sections which are to be connected by the electromagnetic switches o with the feeder and that after the first rush of current through the coils to quickly close the switches the resistances can be automatically cut in circuit with the coil, whereby the switches are held in their closed positions with comparatively small current. \V hen the resistances have been mounted on the car, they have been .)ermanently in circuit, thus causing considerable waste of energy, as it requires a large current to energize the electroinagnet through the resistance, and this large current contin ues to flow after the switch is closed, whereas a much smaller current could do the work. Hitherto it has not been considered possible to automatically control the resistances when carried by the car.

My invention consists in automatically cutting the resistances carried by the car in circuit with the electromagnet coils of the switches after said coils have been energized. The advantageous result is that the total number of resistances used in a system is proportional to the number of cars instead of to the number of electromagnetic switches, and there is no waste of energy in the reduced number of resistances, as they are automatically inserted in series with the coils afterthe switches are closed quickly by a large current to cut down the current to a degree just sufficient to hold the switches closed. The practical dii'iiculty in obtaining this solntion will readily be appreciated when it is observed that in the case of resistances embodied with the switches along the way as the car progressively engages advance conductor-sections there are progressive changes in the relation between the stationary and moving parts of the system, which has been taken advantage of, as stated, in automatic al y cutting in resistances after their coils have been energized; but in the case of resistances carried on the car there is no change of relation between the car and the resistances carried thereby and which are required to be automatically inserted in series with the switch-coils. This difficulty I have solved by providing a switch on the car, by which the car resistance is short-circuited as the collectingshoe is about to engage with an ad: Vance conductor-section, and soon as current is admitted to that conductor-sectionthe o short-circuiting switch on the car is opened, whereby the resistance is inserted in series with the switch-coil. This switch on the car must normally short-circuit the resistance when all the electromagnetic switches of the 5 roadway are disconnected from the feeder in order that the auxiliary source on the car may be utilized to energize the coils of the feeder-switches; but in this case, as the auxiliary source is necessarily connected with too the collecting means which supplies the carmotors, there should be provided means for preventing the sudden rush of current flowing through the collector when the feederswitch is closed from short-circuiting to return through the auxiliary source on the car. This object is accomplished, as described herein, by inserting a resistance 7" between the auxiliary source and its connection with the collector-shoe which supplies the car-motors with current.

The drawing is a partially diagrammatic view in order to show more clearly the electrical connections and relations of parts. There are no novel structural features, and I intend that any suitable switches or other apparatus well known to engineers at this time may be employed to embody the inven tion in commercial apparatus.

The particular system shown for the purpose of illustration is that in which the switches W W located along the way, have their coils connected in shunts to the return around the car-motors, two parallel lines of conductor-sections being employed, the sections in oneline being connected to the switchcoils'and the sections in the other line being connected to the feeder-switches W W The collecting means carried by the car for this particular system comprises two pairs of shoes 0 O and C 0 whereby a connection will always be had between the car and the conductor-sections. The car-motors are illustrated at M and are operated by any suitable controller, as K. In shunt with the controller K is G, the auxiliary source of current for initially connecting a conductor-section with the feeder. In the relative positions of the car and conductor-rails both switches W W are closed. All the parts above the conductor-rails are carried by the car, including the resistances R and R which are automatically cut in circuit with the switch-coils P P after said coils have been energized in either direction of movement of the car. If it is desired to operate the car normally only in one direction, the arrangement about to be described may be considerably simplified without material modification. In order, however, that the car. may be operated normally in either direction, there is provided a reciprocable switch-carrying member, which comprises a centralpart of insulation N, integral with two cores D and D on its ends. On the ends of these cores are switch-pieces T and T suitably insulated from the cores. The collecting-shoes C and G which engage the serviceconductor sections L L and neither of which is sufficiently long to bridge across from L to L, are connected through the coils O and 0 respectively, with the motor-controller K and contacts of the switches T and T The collecting-shoes O and G which engage the energizing-conductor sections L and L and neither of which is sufficiently long to bridge across from L to L are connected to the J other contacts of the switches T and T respectively. As shown, the resistances R and R are connected to the contacts of these switches T and T A spring or its equiva lent I is adapted to hold the reciprocable switch member in its extreme right-hand position when no current is flowing through either of the coils O or 0 so that current from the auxiliary source may be shunted aroundthe resistance R to initially energize the switch-coil P The auxiliary source carried by the carcomprises a shunt-wound generator G, having one terminal connected to the return atR and the other to the contact of the switch S. This generator is driven by an air-motor E and is adapted to generate a higher electromotive force than that of the line. The airmotor is supplied with compressed air through a pipe P, which supply is controlled by a valve V, which is combined with the switch-piece of the switch S, whereby air is admitted to the motor, and simultaneously the circuit of the generator is completed and the switch S closed. In practice in starting thecar the motorman will simply hold the valve V open for one or two seconds. In that short time current will flow from the generator G through the resistance 1", through the switch T in short cireuit to the resistance R to the collector-shoe O conductor-section L, and the switch-coil P to the return at R, thereby closing the switch W Current will then flow from the switch WV to the conductor-section L, the collector-shoe O and the coil 0 to the controller K, but is opposed by the resistance r to prevent a short circuit to the return through the armature of the generator G before the motorman has opened the switch S. The generator G and air-motor E may be of any suitable design, as those supplied by the trade in a set of one piece of apparatus. When the current flowed through the coil 0 the core D was drawn to the left, thereby withdrawing the switch-piece T from its contacts and inserting the resistance R in series between the switch W and the coil P which holds the switch closed. The switch W is thereby held closed with a minimum expenditure of energy. It will be noted that the cores 0 and O on the car mutually oppose each other, and, as shown, the reciprocable member is in its middle or balanced position, both switchpieces P and P being separated from their contacts. This is the conditionv whenever both feeder-shoes C and O engage conductorsections which are connected with the feeder by closed switches W. Let us assume that before the car has moved to the left to the position shown both shoes (3 and O engage the conductor-section L that both shoes C and O engage the conductor-section L and that the car is at rest in this position. The coil P having been energized by the auxiliary source on the car, as above described, to close the switch WV current will flow through the coils O and O to maintain the reciprocable member in its middle position, just as in the position shown, where the shoe 0 engages the section L and the shoe 0 engages the IIO evaoso section L. If the controller K is now operated so that the car moves to the left, the shoes 0 and G will be carried off from the respective sections L and L The coil 0 is thus denergized, and the reciprocable memher is moved to the left by the action of the coil 0 on its core D to short-circuit the resistance R preparatory to permitting the current flowing in the motor-circuit to flow in shunt to the car-motors directly through the coilP of the advance switch WV to the return R. As soon as the shoe O engages the section L this current will flow through the switch-piece D, the shoe 0, section L, and coil P to the return to close the switch W, whereby cur rent will flow from the feeder F through the switch WV, the section L shoe O and coil 0 to the motor-circuit, so that the coil 0 pulls the core D to the right, thereby inserting the resistance R in series with the coil P to cut down the current flowing through said coil and to permit the switch WV to be held closed by a relatively small current. a This is the situation shown in the drawing, the reciprocable member being in its balanced position. As the car continues in its movement to the left the shoes 0 and 0 pass from the sections L and L whereby the coil 0 is deenergized, and the reciprocable member is pulled by the spring Iand coil 0 to the right to short-circuit the resistance R As the shoes 0 and C engage with the sections L and L current will tendto flow in shunt to the car-motors through the switchpiece T the shoe C and the section L to the coil P; but the shoe 0 simultaneously engages the section L thereby energizing the coil 0 moving the reciprocable member to the left to its intermediate position, and inserting the resistance R in the circuit. The operation just described with respect to the coil 0 is not essential for the operation of the car to the left; but this construction is adopted in order that the car may operate in the opposite direction. If now the controller K is operated to propel the car to the right from the position where all the shoes engage the sections L and L the shoes (J and U will pass to the right from off the sections L and L thereby deenergizing the coil 0 and permitting the spring I and coil 0 to move the switch piece T to the right to short-circuit the resistance R The shoes C and C then engage the sections L and L and current flows in the motor-circuit in shunt to the carmotors through the switch-piece T shoe 0 section L and coil 0 to the return to close the advance switch W whereby current flows from the feeder through the switch W section L shoe O, and the coil 0 to the motor-circuit. The coil 0 being thus energized opens the switch '1 and inserts the resistance R in circuit with the coil P cutting down the current flow through the latter antipermitting the switch W to be held closed with a relatively small current.

The operation with respect to shoes C and 0 when the car is moving to the right is similar to that described with respect to shoes C and 0 when the car is moving to the left.

Owing to the use of the spring I or its equivalent to short-circuit one resistance, so that the auxiliary source can initially pick up a feeder-switch, the coil 0 should have one or two more turns than the coil 0 in order that in normal operation the reciprocable member may be held in its intermediate position. The difference between the number of ampere-turns of the coils need be very slight, as the spring and the reciprocable member are very small in proportion to the current which flows through these coils. Features which form no part of this invention and which it is advisable to employ in systems of this nature are also shown. Among these are the toggles H and H connected with the switches W and 7 to operate the secondary breaks Q and Q Magnetic blowout coils B and B are also connected in shunts around the main switch-contacts in order to blow out the are formed at the contacts of the secondary breaks.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric railway, the combination with the feeder,of conductor-sections, electromagnetic switches for connecting the feeder with said sections, a resistance carried by the car, and means for automatically cutting said resistance into circuit with the successive switch-coils after the latter have been energized.

2. In an electric railway, the combination with the feeder, of conductor sections, switches for connecting the feeder with said sections, auxiliary conductor-sections, coils connected between said auxiliary sections and the return for actuating said switches, a resistance carried by the car, and means for an tomaticaily cutting said resistance into circuit with the successive switch-coils after they have been energized.

3, In an electric railway, the combination with the feeder,of conductor-sections, electromagnetic switches for connecting the feeder with said sections, a resistance carried by the car, and means controlled by the current flowing from a closed switch for cutting said resistance into circuit. with the coil of that switch.

4. In an electric railway, the combination with the feeder,of conductor-sections,electromagnetic switches for connecting the feeder with said sections, a resistance carried by the car, a switch on the car, and a coil on the car which is connected with said switches, and which actuates said car-switch to cut said resistance in circuit with the coils of the electromagnetic switches.

5. In an electric railway, the combination with the feeder,of conductcr-sections, electro magnetic switches for connecting the feeder with said sections, a resistance carried by the car, a switch on the car, and a coil on the car which is connected to the electromagnetic switches through the car-collector, and which actuates the car-switch when an electromagnetic switch is closed to insert the resistance in circuit with the coil of that electromagnetic switch.

6. In an electric railway, the combination with the feeder,of conductor-sections,electromagnetic switches for connecting the feeder with said sections, a resistance, and electromagnetic means which is energized by the closing of said switches to insert the resistance in circuit with the coils of said switches.

7. The combination with an electromagnetic switch, of a resistance, and an auxiliary electromagnetic switch having its coil in circuit with the first switch, whereby the resist-' ance is cut into circuit with the coil of the first switch after the first switch is closed.

8. The combination with the feeder-switches of a sectional conductor-railway, of electromagnetic switches having their coils con nected in branches around the car-motors, and adapted to connect the feeder with the conductor-sections, a resistance on the car, and means for automatically inserting the resistance in series with the coils of the switches when the latter are closed.

9. The combination with a feeder-switch, of a coil for'closing it, and a resistance on the car which is cut into circuit with the coil when the latter has closed the switch.

10. The combination with a feeder-switch, of a coil for closing the switch, said coil being in a branch of the circuit closed by the switch, a resistance, and a coil in the circuit closed by the switch which inserts the resistance in series with the first coil.

11. In an electric railway, the combination with the feeder, of conductor-sections,electromagnetic switches for connecting the feeder with said sections, resistances on the car, and differentiating-coils closed by said switches for inserting said resistances in circuit with the coils of said switches.

12. In an electric railway, the combination with the feed er, of conductor-sections,electromagnetic switches for connecting the feeder with said sections, two resistances carried by the car, a reciprocable member, a coil which moves said member in one direction to shortcircuit one resistance and cut in the other resistance, and a coil which moves said member in the opposite direction to short-circuit the latter resistance and cut in the former resistance.

13. In an electric railway, the combination with the feeder, of conductor-sections,electromagnetic switches for connecting the feeder with said sections, two divided collecting devices carried by the car, two resistances carried by the car and adapted to be inserted only between .the halves of each collecting device,a reciprocable member which normally tends to short-circuit one resistance, a coil which moves the switch-piece to cut in that resistance and short-circuit the other resistance, and a coil which moves the switch-piece to cut in the latter resistance and short-circuit the former resistance.

14. In an electric railway, the combination with the feeder, of conductor-sections,electromagnetic switches for connecting the feeder with said sections, two divided collecting devices carried by the car and connected to the car-motors,two resistances,and two mu tuallyopposing coils carried by the car, one coil and one resistance being connected between the two parts of each collecting device; and a reciprocable member actuated by the coils for short-circuiting said resistances.

15. In an electric railway, the combination with the feeder, of service conductor-sections, electromagnetic switches for connecting the feeder with the said sections, energizing conductor-sections, two pairs of collecting devices which consist each of a shoe engaging the service conductor-sections and a shoe engaging the energizing conductor-sections, a coil and a resistance connected between one service-shoeand its fellow energizingshoe, an opposing coil and a resistance connected between the other service-shoe and its fellow energizing-shoe, and a reciprocable member actuated by said coil to short-circuit said resistances.

16. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches for connecting the feeder with said sections, collecting means carried by the car for supplying current from the conductor-sections to the car-motors and switchcoils, an auxiliary source on the car of a higher electromotive force than that of the feeder, for initially energizing the coils of said switches, and a connection between said source and the collecting means which includes a resistance adapted to oppose the electromotive force of the feeder and protect the auxiliary source.

17. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means carried by the car to convey current from the con ductor-sections to the car-motors and switchcoils, an auxiliary source of current carried by the car and adapted to be connected to said collecting means, for initially energizing said switch-coils, and means for preventing injury to said-auxiliary source by the rush of feeder-current following the closing of a switch and before the auxiliary source can be disconnected.

18. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means carried by the car to supply current to the car-motors and switch-coils, a resistance normally out of the circuits of the switch-coils, an auxiliary source on the car for initially energizing the switch-coils when said resistance is out of circuit, a resistance between said auxiliary source and the feeder, and means for including the first resistance in series with said coils after their preliminary energization.

19. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means for the carmotors and switch-coils, a resistance normally out of the circuits of the switch-coils, an auxiliary source on the car and in shunt to the car-motors, for initially energizing the switch-coils, a resistance between said source and the feeder, and means for including the first resistance in series with the switch-coils after their preliminary energization.

20. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means for supplying current to the car-motors and switchcoils, an electric machine on the car in shunt to the car-motors for initially energizing said switch-coils, and a resistance in said shunt to prevent a short circuit from the feeder through said machine.

21. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means carried by the car for supplying current to the carmotors and switch-coils, an electric machine for initially energizing said switch-coils, and a compressed-air motor for operating said machine.

22; In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means for supplying current to the car-motors and switchcoils, an electric machine on the car in shunt to the car-motors for initially energizing said switch-coils, and a compressed-air motor for operating said machine.

23. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means carried by the car for supplying current to the carmotors and switch-coils, an electric machine for initially energizing said switch-coils, a compressed-air motor for operating said machine, and a device for simultaneously coniii trolling the circuit of said machine and the supply of air to said airunotor.

24. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, collecting means carried by he car for supplying current to the carmotors and switch-coils, an electric machine on the car in shunt to the car-motors for initially energizing the switch-coils, and a compressed-air motor for operating said machine.

25. In an electric railway, the combination with the feeder, of cond uctor-sections, electromagnetic switches, collecting means carried by the car for supplying current to the carmotors and switch-coils, an electric machine on the car adapted to generate a higher electromotive force than the line, and a resistance between said machine and the feeder to prevent the line from short-circuiting said machine.

26. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic means for progressively connecting the feeder with said sections as the car proceeds, a resistance carried by the car, and means for automatically cutting said resistance in circuit with the electromagnet-coil after the feeder has been connected with a conductor-section.

27. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic switches, a resistance on the car, a permanent shunt from the motorcircuit to the return, which shunt includes the coils of said switches, and an electromagnetic switch on the car which cuts said resistance in circuit with the energized coils of said switches.

In witness whereof I have hereunto set my hand this 19th day of February, 1901.

SAMUEL B. STEWART, JR.

Witnesses:

BENJAMIN B. HULL, EDWARD WILLIAMS, Jr. 

